United States Nuclear Regulatory Commission - Protecting People and the Environment

95161 LIMITORQUE CORPORATION         29060 07-13-95 OTH
LICENSEE: LIMITORQUE CORPORATION
SITE: .LIMITORQUE CORPORATION        .        EN NUMBER:29060
DOCKET:                                  EVENT DATE: 07-13-95
RX TYPE:                                 EVENT TIME: 00:00
VENDORS:                                NOTIFY DATE: 07-13-95
EMERGENCY CLASS: N/A  REGION: 2 STATE: VA      TIME: 16:30
OPS OFFICER: JOSEPH SEBROSKY
10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH

IN ACCORDANCE WITH 10 CFR PART 21, LIMITORQUE CORPORATION OF
LYNCHBURG, VA, REPORTED A POTENTIAL DEFECT IN SMB/SB/SBD-00
MOTOR-OPERATED VALVE ACTUATORS.
                                                                 
LIMITORQUE DISCOVERED, THROUGH A NOTIFICATION FROM THE TENNESSEE
VALLEY AUTHORITY, THE POSSIBILITY OF THE OUTSIDE CLUTCH TRIPPER
BECOMING WEDGED AGAINST THE ACTUATOR HOUSING AND PREVENTING THE
ACTUATOR FROM SHIFTING TO ELECTRICAL FROM MANUAL OPERATION WHEN
THE MOTOR IS ENERGIZED.  LIMITORQUE CONTENDS THAT THIS CONDITION
COULD BE REPORTABLE DEPENDING ON THE OPERATING PRACTICES OF THE
LICENSEES.  SPECIFICALLY,
                                                                 
-  A REPORTABLE CONDITION DOES NOT EXIST IF THE INDIVIDUAL
LICENSEE'S PRACTICES ENSURE ACTUATOR ELECTRICAL (MOTOR) OPERATION
VERIFICATION AFTER BEING IN THE MANUAL (HAND WHEEL) MODE.
                                                                 
-  THE POTENTIAL FOR A REPORTABLE CONDITION EXISTS IF THE
INDIVIDUAL LICENSEE'S PRACTICES DO NOT ENSURE ACTUATOR (MOTOR)
OPERATION VERIFICATION AFTER BEING IN THE MANUAL (HAND WHEEL)
MODE.
                                                                 
LIMITORQUE'S INVESTIGATION OF THE CONDITION SHOWS THAT
SMB/SB/SBD-00 HOUSINGS HAVING A CAST DATE OF 1979 OR EARLIER MAY
HAVE THE POTENTIAL FOR THIS WEDGING, AND INSTALLATION OF A
'TRIPPER STOP' WILL PREVENT THE PROBLEM.  SMB/SB/SBD-00 HOUSINGS
HAVING A CAST DATE OF 1980 OR LATER WILL NOT HAVE THE POTENTIAL
FOR THE PROBLEM.
                                                                 
LIMITORQUE IS IN THE PROCESS OF MAKING A WRITTEN NOTIFICATION TO
THE AFFECTED NUCLEAR UTILITIES OF THE PROBLEM.

Page Last Reviewed/Updated Thursday, March 29, 2012